Senior Product Engineer; AI

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Base pay range:

This range is provided by Plain. Your actual pay will be based on your skills and experience — talk with your recruiter to learn more.

We’re in a rare spot. Plain is already powering support for high‑growth companies with a lightning‑fast, deeply scalable platform. AI has been part of our DNA from the start. Now we’re doubling down to define how it shapes every layer of modern customer support.

We’re looking for a customer‑obsessed Senior Product Engineer to help take our AI ambitions to the next level. You’ll build the infrastructure that helps us build AI features quickly, safely and with confidence. You’ll own problems end to end, and play a key role in building a category‑defining product.

In this role, you will:

• Own and ship AI features such as our agents, assistants, insights and more — from concept to production.
• Design and implement backend services for AI integrations and data pipeline.
• Build robust APIs and abstractions for internal AI usage.
• Drive system scalability: caching, optimization, processing patterns, etc.
• Contribute and drive the evolution of the infrastructure for AI including architecture, evaluation and iteration pipelines.
• Solve complex AI challenges around AI accuracy, reliability, and quality — using rigorous quantitative approaches.
• Advocate for our work externally – writing, speaking, and engaging with the broader AI community.

• Are an experienced backend engineer who’s shipped AI products in the OpenAI & Anthropic era – especially text and data‑heavy AI applications.
• Have hands‑on experience with LLM orchestration and LLM API optimization (costs, latency, etc.).
• Are familiar with RAG architectures and technologies.
• Have AI observability experience. AI isn’t just about shipping features that sound great – it’s about knowing, conclusively, if they’re making things better.
• Have a clear perspective on what makes a great AI product. We want to apply AI with precision, nuance, and real impact – not as a gimmick.
• Are product‑minded and customer‑focused in how you build software.
• Measure your success by user impact, not just technical elegance.
• Are self‑driven, impact‑focused, and thrive in a fast‑moving, high‑ownership environment.
• Bonus: you have experience with agent frameworks and design.

• Have primarily academic or research ML/AI experience. This role’s looking for someone with applied AI experience.
• Think AI for support is just chatbots and deflection. B2B support is complex – we want AI through the platform, not just automating conversations.
• Struggle with ambiguity. We’re an early‑stage startup. Things change quickly, and often, knowing what to work on is as important as the work itself.
• Prioritize working with the latest tech for its own sake. We choose tools that make us productive – not what’s trendy. (Postgres is great.)
• Are looking for a management role. This is a hands‑on individual‑contributor position.
• Want the perks of a big company. We offer competitive compensation for our stage, but we’re a startup – this is a different kind of opportunity.

Mid‑Senior level

Full‑time

Engineering and Information Technology

Software Development